Automatic feeder for coal burning furnaces



Nov. 22, 1932. F. A. STOLTE AUTOMATIC FEEDER FOR COAL BURNING FURNACES Filed Oct. 5. 1929 '2 Sheets-Sheet l INVENTOR. FldflU/ZH. (57301176, BY

A TTOR NE Y5 Nov. 22, 1932. F. A. STOLTE AUTOMATIC FEEDER FOR COAL BURNING FURNACES Filed Oct. 5. 1929 2 Sheets-Sheet 2 IN V EN TOR. Frazier/016A .6 Z 0/ Z 6 j l ovviw A TTORNEYS Patented Nov. 22, 1932 UNITED STATES PATENT OFFICE FREDERICK A. STOLTE, OF INDIANAPOLIS, INDIANA, ASSIGNOR TO STOLTE STOKER CORPORATION, OF INDIANAPOLIS, INDIANA, A CORPORATION OF INDIANA AUTOMATIC FEEDER FOR COAL BURNING FURNACES Application filed October 5, 1929. Serial No. 397,506.

My invention relates to improvements in automatic feeders or stokers for coal-burning grates, particularly adapted for furnaces and boilers.

One of the objects of my invention is to provide an automatic feeder for coal which delivers the fuel to the grate automatically from beneath the fire and which will maintain on the grate a predetermined amount of fuel, means being provided for stopping the feeding of the fuel when the amount of fuel on the grate reaches a predetermined maximum.

For the purpose-of disclosing my invention, I have illustrated one embodiment thereof in the accompanying drawings, in which:

Fig. 1 is a plan view of a feeder embodying my invention, the fire-pot of the furnace being shown in section and certain portions of the grate being broken away;

Fig. 2 is a longitudinal sectional view of the feeder;

Fig. 3 is a detail section on the line 33 of Fig. 2, and

Fig. 4 is a detail view, partly diagrammatic showing the automatic cut-ofi' for the feeder.

In the embodiment illustrated, I provide the usual fire-pot 1 which is mounted above an ashpit 2 of the usual construction, and has arranged at its bottom a rotatably mounted grate 3. This grate may be of the fiat or cone type or whatever is desirable. A hopper 4 is provided exteriorly of the furnace which may be cylindrical or of any suitable shape and is provided with a sloping rear wall 5 and sloping side walls 6 which converge to a channel 7 in the bottom of the hopper. Operating within this channel is a plunger or piston 8, preferably rectangular in shape and having its forward upward edge chamfered as at 9. This piston is reciprocated in the bottom of'the hopper by means of a suitable electric motor 10 driving an eccentric 11 connected by a piston rod 12 with the plunger 8. The hopper is provided with a forwardly ext-ended feed spout 12' which may be in the form of a hollow tubular casting screw threaded at its rear end into a 50 threaded socket 13 in the front wall of the hopper. The forward end of the feed spout turns upwardly so that its delivery end 14 may project through a center opening in the grate 3. This feed spout extends through an opening in one of the side walls of the ash-pit 2 and is supported at its forward end thereby.

The grate is rotatably mounted within the fire-pot 1 and to this end, I provide on the spout 12' a yoke 15 which straddles the same and is supported thereby and which at, its opposite ends, carries rollers 16 and 17 on which the bottom of the grate rests. A third roller 18 diametrically opposite and medially between the rollers 16 and 17 supports the grate from its opposite side. This roller is mounted on a pivoted lever 19, supported on the pivot rod 20 mounted in the brackets 21 and 22. One of the brackets 21 is secured on the inside of an ash-pit wall and the other bracket 22 is secured on the exterior of the ash-pit wall, the pivot rod 20 being adapted to pass through the ash-pit wall and the furnace covering and having mounted on its outer end a counter-balancing lever 23. This lever carries an adjustable counter-balancing 7 5 weight 24 to counter-balance the weight of the grate and is also provided with a mercury switch 25, which when the lever 23 is tilted upwardly under the influence of the downward tilting movement of the grate opens the circuit through the motor 10, but maintains the circuit closed so long as the weight 24 over-balances the weight of the grate 3 and maintains the same in its normal horizontal position.

The reciprocating movement of the piston or plunger 8 feeds the fuel forward through the feed spout 12', and to assist in this feeding movement. the piston is provided with a pair of side bars 26 which project into the feed spout and lie in grooves 27 formed in each side of the feed spoutand below the horizontal center of the spout.

In order to evenly distribute the fuel over the grate, the grate is rotated during the feed- 95 ing of the fuel thereto and to this end a'bottom annular flange 28 is provided on the underside of the grate having ratchet teeth 29 on its side. These ratchet teeth are engaged by a pawl 30 which is reciprocated by 100 means of a connection between the motor 10 and the pawl comprising a link rod 31, the rear end of which is connected to a horizontally disposed pivoted lever 32. The posite end of'this lever is connected by a k 33 with one end of a pivoted lever 34, the 0pposite end of which is connected to the connecting rod 12. By this arrangement the grate is rotated step by step as long as fuel is fed thereto.

I claim the following:

1. The combination with a fire-pot and a grate tiltably supported therein, of: a counterbalanced lever normally supporting one end of said grate in its raised position, means for automatically delivering fuel to said grate, an electric motor for operating said means and aswitch operated by said lever when the grate is tilted by the weight of the fuel for opening the circuit through said motor.

2. The combination with a fire-pot and a grate, of means for supportin said grate at spaced apart points, means or supporting said grate at a third point, said 'means being depressible by the weight of the fuel on the grate, means for automatically feeding fuel to said grate, an electric motor for operating said means and an electric switch operated by said depressible' supporting means for controlling the circuit through said motor. 1 I

3. The combination with a fire-pot and a grate, of means for supportin said grate at spaced apart points, a third means for supporting said grate located medially of said first mentioned means and diametrically opposite said supporting means, said third means being depressible'under the weight of the fuel. on said grate, means for feeding the fuel to said grate, an electric motor for operating said means and a switch operated by said depressible supporting means for controlling the circuit of said motor.

4. The combination with a fire-pot, of a grate rotatably and tiltably mounted therein, means for automatically'delivering fuel to said grate and means operated by the tilting of said grate for controlling the operation of said fuel delivery means.

5. The combination with a fire-pot, of a grate rotatably and tiltably mounted therein, a feed spout arranged beneath said grate and delivering to the top of said grate, means for dehvering fuel through said feed spout, an electric motor for operating said means, and means operated by the tilting of said grate for controlling the circuit of said motor.

In witness whereof, I, Fnnonnrox A. STOLTE have hereunto set my hand at Indianapolis, Indiana, this 17th day of September, A. D. one thousand nine hundred and twenty nine- FREDERICK A. STOLTE. 

